The history of bacon

Where does bacon come from? Actually, where did the pigs come from? Science. …

Wild boar were domesticated to become pigs at least seven times independently, according to research published this week (subscription required). Until now, it was perceived wisdom that pigs were domesticated from wild boar only twice ? in Europe and South East Asia, and that pigs traveled with man on his way round the planet. That view is being challenged, after scientists compared the mitochondrial DNA sequences from almost 700 wild and domestic pig species from around the globe and discovered that domestication had happened at least seven times, ranging from Europe to New Guinea. It is suggested that as man traveled he domesticated wild boar as he found them, rather than bringing pigs along for the journey.

Malaria map looks bad for Africa

A study published in Nature this week has raised concerns that the WHO?s goal of halving the number of malaria infections by 2010 may notbe reached. The authors of the study looked at the global distribution of malaria, and the number of people infected compared to previous years. They estimate that 2.2 billion people live at risk from P. falciparum, and that 515 million people worldwide suffer attacks annually. The controversy springs from the jump in numbers compared to the official 1999 WHO estimate of 273 million cases. Officials at the WHO have responded to the findings and say that they revised their estimates in 2000 to 300 million-500 million, and that they are confidant they will meet their target of minimizing the impacts of this disease.

Perhaps not altogether surprisingly, this work shows that once again Africa is bearing the brunt of this disease. ?Although over a billion people are exposed to the disease in South East Asia, 70% of clinical cases are in sub-Saharan Africa. ?

Meanwhile, cancer plays no favorites

Cancer rates in poor countries are similar to those in the developed world, according to a new report. Despite common preconceptions that they would be lower, the study from the International Agency for Research on Cancer, showed that with increasing life expectancy in the developing world came increased cancer rates. Lung cancer in particular is on the increase, as tobacco companies focus on new markets. Only half of all cases are from the developed world now, down from 70% 25 years ago.

Where you live and what you eat have a large influence on the types of cancer you are at risk from. Richer countries have more breast, colon, rectum and prostate cancer, whereas poorer countries have a greater incidence of cancers of the liver, stomach, and esophagus. Men and women in the US are at the greatest risk of developing cancer, accounting for 14.5 million cases each year, although the high number is almost certainly in part due to an aware population and advanced detection.

Millions at risk of drought in future

The WWF is raising alarms about the melting of Himalayan glaciers and the implications this has for hundreds of millions of people who depend on the meltwater for drinking water. Many of the inhabitants of the most populous corner of Earth depend on the spring melt-water to swell the rivers they depend on for drinking water and crop irrigation.

The Indus, Ganges, Brahmaputra, Mekong, Thanlwin, Yangtze, and Yellow rivers are all estimated to be in retreat. Proponents of climate change have pointed to fresh water shortages in certain areas as key concerns in the future. As more water is liberated from ice precipitation patterns are expected to change, with knock-on effects for ecosystems.

In other climate change news, pictures of Mount Kilimanjaro free of its icecap for the first time in 11,000 years is being used to focus the attention of policy makers from around the world, meeting in London this week.